LXR linux/fs/freevxfs/vxfs

   1/*
   2 * Copyright (c) 2000-2001 Christoph Hellwig.
   3 * All rights reserved.
   4 *
   5 * Redistribution and use in source and binary forms, with or without
   6 * modification, are permitted provided that the following conditions
   7 * are met:
   8 * 1. Redistributions of source code must retain the above copyright
   9 *    notice, this list of conditions, and the following disclaimer,
  10 *    without modification.
  11 * 2. The name of the author may not be used to endorse or promote products
  12 *    derived from this software without specific prior written permission.
  13 *
  14 * Alternatively, this software may be distributed under the terms of the
  15 * GNU General Public License ("GPL").
  16 *
  17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
  21 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27 * SUCH DAMAGE.
  28 */
  29
  30/*
  31 * Veritas filesystem driver - inode routines.
  32 */
  33#include <linux/fs.h>
  34#include <linux/buffer_head.h>
  35#include <linux/pagemap.h>
  36#include <linux/kernel.h>
  37#include <linux/slab.h>
  38#include <linux/namei.h>
  39
  40#include "vxfs.h"
  41#include "vxfs_inode.h"
  42#include "vxfs_extern.h"
  43
  44
  45struct kmem_cache               *vxfs_inode_cachep;
  46
  47
  48#ifdef DIAGNOSTIC
  49/*
  50 * Dump inode contents (partially).
  51 */
  52void
  53vxfs_dumpi(struct vxfs_inode_info *vip, ino_t ino)
  54{
  55        printk(KERN_DEBUG "\n\n");
  56        if (ino)
  57                printk(KERN_DEBUG "dumping vxfs inode %ld\n", ino);
  58        else
  59                printk(KERN_DEBUG "dumping unknown vxfs inode\n");
  60
  61        printk(KERN_DEBUG "---------------------------\n");
  62        printk(KERN_DEBUG "mode is %x\n", vip->vii_mode);
  63        printk(KERN_DEBUG "nlink:%u, uid:%u, gid:%u\n",
  64                        vip->vii_nlink, vip->vii_uid, vip->vii_gid);
  65        printk(KERN_DEBUG "size:%Lx, blocks:%u\n",
  66                        vip->vii_size, vip->vii_blocks);
  67        printk(KERN_DEBUG "orgtype:%u\n", vip->vii_orgtype);
  68}
  69#endif
  70
  71
  72/**
  73 * vxfs_blkiget - find inode based on extent #
  74 * @sbp:        superblock of the filesystem we search in
  75 * @extent:     number of the extent to search
  76 * @ino:        inode number to search
  77 *
  78 * Description:
  79 *  vxfs_blkiget searches inode @ino in the filesystem described by
  80 *  @sbp in the extent @extent.
  81 *  Returns the matching VxFS inode on success, else a NULL pointer.
  82 *
  83 * NOTE:
  84 *  While __vxfs_iget uses the pagecache vxfs_blkiget uses the
  85 *  buffercache.  This function should not be used outside the
  86 *  read_super() method, otherwise the data may be incoherent.
  87 */
  88struct vxfs_inode_info *
  89vxfs_blkiget(struct super_block *sbp, u_long extent, ino_t ino)
  90{
  91        struct buffer_head              *bp;
  92        u_long                          block, offset;
  93
  94        block = extent + ((ino * VXFS_ISIZE) / sbp->s_blocksize);
  95        offset = ((ino % (sbp->s_blocksize / VXFS_ISIZE)) * VXFS_ISIZE);
  96        bp = sb_bread(sbp, block);
  97
  98        if (bp && buffer_mapped(bp)) {
  99                struct vxfs_inode_info  *vip;
 100                struct vxfs_dinode      *dip;
 101
 102                if (!(vip = kmem_cache_alloc(vxfs_inode_cachep, GFP_KERNEL)))
 103                        goto fail;
 104                dip = (struct vxfs_dinode *)(bp->b_data + offset);
 105                memcpy(vip, dip, sizeof(*vip));
 106#ifdef DIAGNOSTIC
 107                vxfs_dumpi(vip, ino);
 108#endif
 109                brelse(bp);
 110                return (vip);
 111        }
 112
 113fail:
 114        printk(KERN_WARNING "vxfs: unable to read block %ld\n", block);
 115        brelse(bp);
 116        return NULL;
 117}
 118
 119/**
 120 * __vxfs_iget - generic find inode facility
 121 * @sbp:                VFS superblock
 122 * @ino:                inode number
 123 * @ilistp:             inode list
 124 *
 125 * Description:
 126 *  Search the for inode number @ino in the filesystem
 127 *  described by @sbp.  Use the specified inode table (@ilistp).
 128 *  Returns the matching VxFS inode on success, else an error code.
 129 */
 130static struct vxfs_inode_info *
 131__vxfs_iget(ino_t ino, struct inode *ilistp)
 132{
 133        struct page                     *pp;
 134        u_long                          offset;
 135
 136        offset = (ino % (PAGE_SIZE / VXFS_ISIZE)) * VXFS_ISIZE;
 137        pp = vxfs_get_page(ilistp->i_mapping, ino * VXFS_ISIZE / PAGE_SIZE);
 138
 139        if (!IS_ERR(pp)) {
 140                struct vxfs_inode_info  *vip;
 141                struct vxfs_dinode      *dip;
 142                caddr_t                 kaddr = (char *)page_address(pp);
 143
 144                if (!(vip = kmem_cache_alloc(vxfs_inode_cachep, GFP_KERNEL)))
 145                        goto fail;
 146                dip = (struct vxfs_dinode *)(kaddr + offset);
 147                memcpy(vip, dip, sizeof(*vip));
 148#ifdef DIAGNOSTIC
 149                vxfs_dumpi(vip, ino);
 150#endif
 151                vxfs_put_page(pp);
 152                return (vip);
 153        }
 154
 155        printk(KERN_WARNING "vxfs: error on page %p\n", pp);
 156        return ERR_CAST(pp);
 157
 158fail:
 159        printk(KERN_WARNING "vxfs: unable to read inode %ld\n", (unsigned long)ino);
 160        vxfs_put_page(pp);
 161        return ERR_PTR(-ENOMEM);
 162}
 163
 164/**
 165 * vxfs_stiget - find inode using the structural inode list
 166 * @sbp:        VFS superblock
 167 * @ino:        inode #
 168 *
 169 * Description:
 170 *  Find inode @ino in the filesystem described by @sbp using
 171 *  the structural inode list.
 172 *  Returns the matching VxFS inode on success, else a NULL pointer.
 173 */
 174struct vxfs_inode_info *
 175vxfs_stiget(struct super_block *sbp, ino_t ino)
 176{
 177        struct vxfs_inode_info *vip;
 178
 179        vip = __vxfs_iget(ino, VXFS_SBI(sbp)->vsi_stilist);
 180        return IS_ERR(vip) ? NULL : vip;
 181}
 182
 183/**
 184 * vxfs_transmod - mode for a VxFS inode
 185 * @vip:        VxFS inode
 186 *
 187 * Description:
 188 *  vxfs_transmod returns a Linux mode_t for a given
 189 *  VxFS inode structure.
 190 */
 191static __inline__ umode_t
 192vxfs_transmod(struct vxfs_inode_info *vip)
 193{
 194        umode_t                 ret = vip->vii_mode & ~VXFS_TYPE_MASK;
 195
 196        if (VXFS_ISFIFO(vip))
 197                ret |= S_IFIFO;
 198        if (VXFS_ISCHR(vip))
 199                ret |= S_IFCHR;
 200        if (VXFS_ISDIR(vip))
 201                ret |= S_IFDIR;
 202        if (VXFS_ISBLK(vip))
 203                ret |= S_IFBLK;
 204        if (VXFS_ISLNK(vip))
 205                ret |= S_IFLNK;
 206        if (VXFS_ISREG(vip))
 207                ret |= S_IFREG;
 208        if (VXFS_ISSOC(vip))
 209                ret |= S_IFSOCK;
 210
 211        return (ret);
 212}
 213
 214/**
 215 * vxfs_iinit- helper to fill inode fields
 216 * @ip:         VFS inode
 217 * @vip:        VxFS inode
 218 *
 219 * Description:
 220 *  vxfs_instino is a helper function to fill in all relevant
 221 *  fields in @ip from @vip.
 222 */
 223static void
 224vxfs_iinit(struct inode *ip, struct vxfs_inode_info *vip)
 225{
 226
 227        ip->i_mode = vxfs_transmod(vip);
 228        i_uid_write(ip, (uid_t)vip->vii_uid);
 229        i_gid_write(ip, (gid_t)vip->vii_gid);
 230
 231        set_nlink(ip, vip->vii_nlink);
 232        ip->i_size = vip->vii_size;
 233
 234        ip->i_atime.tv_sec = vip->vii_atime;
 235        ip->i_ctime.tv_sec = vip->vii_ctime;
 236        ip->i_mtime.tv_sec = vip->vii_mtime;
 237        ip->i_atime.tv_nsec = 0;
 238        ip->i_ctime.tv_nsec = 0;
 239        ip->i_mtime.tv_nsec = 0;
 240
 241        ip->i_blocks = vip->vii_blocks;
 242        ip->i_generation = vip->vii_gen;
 243
 244        ip->i_private = vip;
 245        
 246}
 247
 248/**
 249 * vxfs_get_fake_inode - get fake inode structure
 250 * @sbp:                filesystem superblock
 251 * @vip:                fspriv inode
 252 *
 253 * Description:
 254 *  vxfs_fake_inode gets a fake inode (not in the inode hash) for a
 255 *  superblock, vxfs_inode pair.
 256 *  Returns the filled VFS inode.
 257 */
 258struct inode *
 259vxfs_get_fake_inode(struct super_block *sbp, struct vxfs_inode_info *vip)
 260{
 261        struct inode                    *ip = NULL;
 262
 263        if ((ip = new_inode(sbp))) {
 264                ip->i_ino = get_next_ino();
 265                vxfs_iinit(ip, vip);
 266                ip->i_mapping->a_ops = &vxfs_aops;
 267        }
 268        return (ip);
 269}
 270
 271/**
 272 * vxfs_put_fake_inode - free faked inode
 273 * *ip:                 VFS inode
 274 *
 275 * Description:
 276 *  vxfs_put_fake_inode frees all data associated with @ip.
 277 */
 278void
 279vxfs_put_fake_inode(struct inode *ip)
 280{
 281        iput(ip);
 282}
 283
 284/**
 285 * vxfs_iget - get an inode
 286 * @sbp:        the superblock to get the inode for
 287 * @ino:        the number of the inode to get
 288 *
 289 * Description:
 290 *  vxfs_read_inode creates an inode, reads the disk inode for @ino and fills
 291 *  in all relevant fields in the new inode.
 292 */
 293struct inode *
 294vxfs_iget(struct super_block *sbp, ino_t ino)
 295{
 296        struct vxfs_inode_info          *vip;
 297        const struct address_space_operations   *aops;
 298        struct inode *ip;
 299
 300        ip = iget_locked(sbp, ino);
 301        if (!ip)
 302                return ERR_PTR(-ENOMEM);
 303        if (!(ip->i_state & I_NEW))
 304                return ip;
 305
 306        vip = __vxfs_iget(ino, VXFS_SBI(sbp)->vsi_ilist);
 307        if (IS_ERR(vip)) {
 308                iget_failed(ip);
 309                return ERR_CAST(vip);
 310        }
 311
 312        vxfs_iinit(ip, vip);
 313
 314        if (VXFS_ISIMMED(vip))
 315                aops = &vxfs_immed_aops;
 316        else
 317                aops = &vxfs_aops;
 318
 319        if (S_ISREG(ip->i_mode)) {
 320                ip->i_fop = &generic_ro_fops;
 321                ip->i_mapping->a_ops = aops;
 322        } else if (S_ISDIR(ip->i_mode)) {
 323                ip->i_op = &vxfs_dir_inode_ops;
 324                ip->i_fop = &vxfs_dir_operations;
 325                ip->i_mapping->a_ops = aops;
 326        } else if (S_ISLNK(ip->i_mode)) {
 327                if (!VXFS_ISIMMED(vip)) {
 328                        ip->i_op = &page_symlink_inode_operations;
 329                        inode_nohighmem(ip);
 330                        ip->i_mapping->a_ops = &vxfs_aops;
 331                } else {
 332                        ip->i_op = &simple_symlink_inode_operations;
 333                        ip->i_link = vip->vii_immed.vi_immed;
 334                        nd_terminate_link(ip->i_link, ip->i_size,
 335                                          sizeof(vip->vii_immed.vi_immed) - 1);
 336                }
 337        } else
 338                init_special_inode(ip, ip->i_mode, old_decode_dev(vip->vii_rdev));
 339
 340        unlock_new_inode(ip);
 341        return ip;
 342}
 343
 344static void vxfs_i_callback(struct rcu_head *head)
 345{
 346        struct inode *inode = container_of(head, struct inode, i_rcu);
 347        kmem_cache_free(vxfs_inode_cachep, inode->i_private);
 348}
 349
 350/**
 351 * vxfs_evict_inode - remove inode from main memory
 352 * @ip:         inode to discard.
 353 *
 354 * Description:
 355 *  vxfs_evict_inode() is called on the final iput and frees the private
 356 *  inode area.
 357 */
 358void
 359vxfs_evict_inode(struct inode *ip)
 360{
 361        truncate_inode_pages_final(&ip->i_data);
 362        clear_inode(ip);
 363        call_rcu(&ip->i_rcu, vxfs_i_callback);
 364}
 365